The invention relates to a filter and more particularly to a siloxane filter for preconditioning exhaust gases delivered to an oxygen probe sensor for an internal combustion engine fueled by bio-gas gasses resulting from organic decomposition.
Gaseous silicon compounds, siloxane, are common components found in bio-gas fuels produced in land fills and digesters. When burned as fuel in an internal combustion engine siloxane deposits are formed on all engine and exhaust system surfaces that come in contact with the exhaust gases. Among other problems these deposits will render engine oxygen probes useless after a short time interval. The oxygen sensor probe is a devise that samples the percent of oxygen remaining in the engine exhaust gases after combustion. It generates an electrical signal, which in turn is used to control engine air and fuel mixture assuring proper emissions, while preventing pre-ignition and/or detonation.
In general, a siloxane filter system for protecting an oxygen probe used in an internal combustion engine that burns bio-gases, when made in accordance with this invention, comprises a stainless steel or other fiber filter removably disposed in a housing. The housing has an inlet port and an outlet port disposed in fluid communication with an exhaust duct in such a manner as to cause exhaust gases to flow through the housing and over the filter. The oxygen probe is disposed in the housing down stream of the filter, causing siloxane in the exhaust gases to be deposited on the stainless steel or other fibers of the filter and essentially siloxane free gases passes over the oxygen probe extending its useful life.